Pneumatic control accelerating pump



Jan. 11', 1949. G. GRIFFON 2,458,990

PNEUMATIC CONTROL ACCELERATING PUMP Filed July 21, 1945 5 z 4 I 3 g p. F5 1:2: 5 1 I 1 2; Q 1

INVENTOI? GA TOIV GR/FFO/V Patented Jan. 11, 1949 ,5

Gaston Grifion, Neuilly-sur Seine, France, as-- Signor to Societe Anonyme Solex, Neuilly-sur- Seine, Seine, Francaa society of France Application July 21,11945,=Serial No. 606,335 In. France October 4, 1944 The present invention relates to pneumatic" control accelerating pumps for usein connection; with carburetors for internal combustion, en-

gines, of the type described in theFrenchpatent application No. 862,794, filed January 8, 1940, by Societe Anonyme Solex. The operationof these pumps is controlled by the vacuum existing inthe induction passage leading to theengine, especially on the downstream side of the carburetor throttle means so as automatically to obtain the introduction of a given amount of additional fuel. into said passage during picking u periods and, if so desired, an increase of the percentage of fuel in the fuel mixture when the pressure in said passage exceeds a given value. Accelerating pumps of this kind have advari- 1 tages over mechanically operated pumps but their 4 cas i (01. 261-34) te dste move it toward the left and that exerted by the depression existing on the downstream side of throttle 2, and; which is transmitted to said space I of the pump through a conduit. I3. This suction tends to move the diaphragm II toward the right.

Diaphragm II carries a valve I4 which is applied uponits seat when the diaphragm is moved toward the right.

Valve I4is adapted to open or close the com munication between chamber 9 and a discharge space I from which fuel is fed into the delivery conduitIG of the pump, this conduit including drawback is that, when the engine, isstopped.

they discharge the amount of fuel presentthere in into the induction passage. This is due to the fact that when the throttle is close to the position corresponding to idling of the engine, and when said engine is not yet stopped, the depression is maximum and causes the pump body to be filled with fuel. -As soon as the engine ,is. stopped, the depression ceases to ,act and the, pump discharges its contents into the carburetor and therefore into the induction passage, which' involves serious difficulties when the engine is to be subsequently started.

The object of the present invention is to 'ob vi;

ate this drawback.

Other objects of my invention will result from the following detailed description of some specific embodiments thereof with reference toqthe way of ex:

appended drawings, given merelyv by ample, and in which: I

Fig. 1 is an axial vertical view of a carburetor provided with a pneumatic control accelerating pump made according to a first embodiment of the invention;

Fig. 2 is a similar view of another embodiment.

In the examples illustrated by the drawings, the carburetor includes a body I, a throttle valve 2, and a well 3 communicating with the venturi acalibrated orifice and opening into the venturi of-the carburetor.

Accordingto my invention, dischargespace I5 is connected, through a by-pass conduit It with thereserve of fuel constituted by the constant level chamber 8, and, in this conduit there is provided a valve, preferably constituted by a ball I9, which is operatively connected with throttle 2 in such manner that said valve is opened, that is to, say ball I9 is away from its seat, when said throttle is in the position corresponding to idling of theengine, or close to this position, While it 1 is closed, that is'to say ball I9 is applied against its seat, for all other positions of said throttle.

Intheembodiment of Fig. 1, delivery conduit I6 communicates permanently with space I5. I make use of a push piecezfl, subjected to the action of a spring 2I through the intermediary of arod Z2-connected by means of a lug 23 with through holes 4. In this well is axially disposed a perforated tube 5 provided at its endwith acalibrated orifice 6. Well 3 communicates through a conduit 1 provided witha calibrated orifice I with a constant level ,chamberydor; any other equivalent feed device. ChamberB also feeds fuel to the accelerating pump through an orifice 8 provided with a valve or ball 8 The pump includes a portion 9 separated from a portion III by a diaphragm II or the like. This diaphragm is subjected tothe influence-of two opposed forces, to wit that of a spring I2 which pushpiecezll. Rod 22 is axially slidable in a passage-24 provided in the body I of the carburetor,

Push piece 20' applies valve I9 against its seat when throttle 2 is in a position intermediate between.the fully opened position and a position close to that corresponding to idling of the engine. .On the contrary, when throttle 2, under the effect of its controlling means, is closer to said idling-position or is in this last mentioned position an arm 25 provided on the pivot spindle of ,the. throttle and moved in the direction of arrow A, comes into contact with sliding rod 22 and pushesit; togetherwith push piece 28, which is interconnected therewith, in the upward direction,. which releases ball I9. Under the pressure of the liquid from the pump, said ball I9 can then open,-coming against its upper seat 26. Thus, passage I8, which leads to chamber 8: is opened, Whereas ball I9, through its being applied against seat 26, prevents fuel from leaking between push piece 20 and the wall of its housing provided in body I. As the section of passage i8 is much greaterthan that of jet I'I provided inthe delivery: conduit .I6'of the pump, it is evident that practically the whole of the fuel discharged by the pump as a consequence of the stopping of the engine is returned to chamber 8. I thus avoid the difficulties that would otherwise be experienced for subsequently starting thesengine; Furthermore, as long as the engine is stopped, the

driver can operate at will the throttle pedal without causing the pump to discharge fuel, which is desirable if it is desired toystartathe engine;

without difiiculty, when saidengine is still Warm. Fig. 2 shows another embodiment in which push-piece 28 is operated by displacementj in. a' direction opposed to that of 1'1. v.llin...ot,l'ier.

words, in this case, when throttle 2 is brought close to the idling position, pushipiece iiii-s moved: downwardly, against the action of springzlfiby arm 25 when the latter is rotated in the direction of arrow B.

Fig. 2 shows the parts'in theposition corresponding to the opening cf'throttleZ beyond the pbsition' close to the idling position above referred t. In thiscase, ball is isjappliedby a spring 2; *againstits seat 28provided at one end 'of' the] by-pass conduit l8 leading to the constantlevel' direction, together with push piece 20- and passage H? is opened.

Advantageously, the inlet of the pumpdischarge conduit I6 is disposed opposite :seat '28 and at a distance thereof'such that, when'ball 1'9 leaves its seat 28 under the action of'push piece 2i], it is applied against aseat- 29' provided on the inlet of delivery conduit 16 In this way, ',I obtain a double effect, since ball til-opens the communication with constant level chamber 8 While it simultaneously closes thedeliverybom duit it? of the pump and vice-verse. that the whole of the fuel discharges by the pump when the engine is stopped is returnedtdohamher 8,

In a general manner, while I have,- in the above description, disclosed What I deem to be 'pi'aotical and eiiicient embodiments of the present in vention, itshould be well understood that frdo' not wish to-be limited thereto asthere'mi'ght be changes made in the arrangement; :disposition and form of the parts without departing from passage onthe downstream side of saidthrottle means, fuel delivery means leading from said pumping means to said passage, fuel discharge means leading from said pumping'means tosaid fuel reserve chamber, and means operatively connected with said throttle means for instantaneously opening said discharge means and simultaneously closing said fuel delivery means-when said throttle means is closed beyond a position close:to:the idling position and closing said dis charge means while simultaneously opening said fuel: delivery means when said x-throttle means is opened, beyond. said first mentioned position;

It follows" 2. For use in connection with an internal combustion engine, a source of fuel, means forming an induction passage leading to said engine and a throttlefor controlling said passage, an accelcrating pump which comprises, in combination,

a pump body, a fuel delivery conduit leading from said body to said passage, a pumping memb'erzmovable in said'body in response to pressure variations in the part of said induction passage on the downstream side of said throttle, a fuel return conduit leading from said pump body to saidsourcesof. fuel-and valve means operatively connected withsaid throttle for simultaneously instantaneously opening said return conduit and ys -closing said delivery conduit when said throttle is .closed. beyond a position close to the idling position and simultaneously closing said return conduit and opening, said delivery conduit when said throttle 'is opened beyond said first mentioned position.

3; In a carburetor including a fuel reserve chamber, an induction passage to the engine and. athrottle, the combination of an aocelerating pump gresponsive to pressure variations on 5 the downstream side of said throttle for effecting an increase in fuel flow to said induction passage in "response to a given drop in intake suction,

fuel delivery means leading from said pumpto said passage," fuel discharge means leading from 30 sa-id' pump to said fuel reserve chamber, andf means operatively connected with said throttle for instantaneouslyopeningsaid discharge means and simultaneously closing said delivery" means whensaid'throttle is closedloeyond aposition close'to the idling one and closing saidfdischargc means: while simultaneously opening said delivery means when said throttle is opened beyond said :ffiI'st mentioned position.

'4.In a carburetor-including an induction pas- :tthrottle' for effecting an increase'in fu'el flow'to said induction passage in response to a given 5 drop in intake suction, fuel delivery means leading fromsaid pump to said passage, fuel-discharge means leading from said pump to a point outside of said induction passage, and a. valve operative'lyconnected with'said throttle for in- #5 stantaneously opening said discharge means and simultaneously closing said delivery means when said throttle is closed beyond a position close to the'idling one and closing-said discharge means while simultaneously opening said delivery means when said throttle is opened'beyond said first mentioned position.

1 GASTON GRIFFON.

REFERENCES CITED e0 -The*following references are of record the file ofthis patent:

i UNITED STATES PATENTS Great-Britain.i;. ..i r.May11-5; 1940 

